


Tria Prima

by CourierNinetyTwo



Series: Modern Magic AU [1]
Category: Fire Emblem Series, Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: F/F
Language: English
Status: Completed
Published: 2020-04-08
Updated: 2020-04-08
Packaged: 2021-03-02 04:48:01
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,871
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23549401
Author URL: https://archiveofourown.org/users/CourierNinetyTwo/pseuds/CourierNinetyTwo
Summary: Edelgard and Lysithea have kept their magic secret for years. There's simply no way someone like Hilda would ever find out.
Relationships: Edelgard von Hresvelg/Lysithea von Ordelia, setup for Hilda/Edelgard/Lysithea
Series: Modern Magic AU [1]
Series URL: https://archiveofourown.org/series/1718044
Comments: 4
Kudos: 111





	Tria Prima

**Author's Note:**

  * For [birdhymns](https://archiveofourown.org/users/birdhymns/gifts).



> A gift for birdhymns from yashkonu!

Edelgard hated crawling through the tunnels under the school.

 _Hate_ might not have been the exact word for such bone-aching fear and soul-chilling disgust, but it was suitable enough to describe their crossroads. She had learned very young that magic came at a cost—and in practice, emotional currency was the easiest to burn. It would have been so simple, were that the only price.

Yet for all the elegant frameworks that made raw magic usable by human hands, she and Lysithea were bound to the crude sort that traded life for power: thirty seconds to flick on a light switch from across the room, or sacrificing a decade for a resurrection. 

Unfortunately, she didn't have enough years left to bring her siblings back.

Even more unfortunate was the fact that she could only find proper spell components in this terrible little labyrinth, where the remnants of far older casting had seeped in through the soil, through wars and graves, down into the dark.

The flashlight from her phone caught on a flicker of red, gleaming past a wealth of cobwebs. " _Finally_."

Shuffling forward on her knees, Edelgard set the phone down to keep the light at the right angle, then fished around for her pocketknife. The lurid crimson crystal wasn't the largest she'd ever found, but it was better than nothing. With care, she chipped away pieces of it into a plastic bag, leaving behind a jagged stump in hopes that it would congeal and grow again.

She tried not to think about the fact that the crystals acted like living things, nor the fact that there were fewer and fewer of them every year. Lysithea was so close to finding a cure, or at least a stopgap—something to give back the time that had been stolen.

Edelgard tucked the slivers away in her jacket next to the knife, then picked up the phone again. Turning around was the worst part; if not for her compact size, it wouldn't even be possible. She bent one knee back as far as possible, bent down while rounding her shoulders, and twisted in one clean movement to face the other way. The tunnel was no less inviting in this direction, but at least it led to the exit.

Saying a prayer for what was left of her leggings, Edelgard started to crawl on all fours, keeping a careful measure in her head. After a hundred yards, she had to divert left, then another two hundred to reach the rusty grate that connected all of this to the university's sewer system. Thankfully, the closest pipes hadn't been used in a generation or two.

She stopped to brush a few stray strands back from her face—even in the dark, the sensation was unsettling—and heard a heavy scrape of flesh on earth. Then another, and yet another, coming her direction.

Discipline overrode panic, and Edelgard pulled out her knife once more, flicking the blade open. Drawing blood for a spell down here was extremely ill-advised, but there had never, _ever_ been another person down here in the tunnels with her. In fact, Edelgard wasn't even sure the noise was a person, for the slow drag forward implied an intimidating weight. She'd heard stories of beasts crawling out of the ground and abducting students, but that was from Lindhart, and he spent ninety percent of their classes high as a kite.

The noise stopped, replaced by staggered breaths. "Fuck me. This was totally a mistake."

Relief and tension wrestled over Edelgard's heart. It _was_ a person, but that still meant someone other than Lysithea knew about the tunnels, and there was no way to know their motives. Even worse, there was no other way to get out, save for crawling forward.

"I can't—fit— _u_ _gh_." The louder and closer the voice became, the more familiar it sounded. Edelgard frowned. "I can't believe I let Claude talk me into this."

Pale eyebrows shot upward. "Hilda?"

Magic burst down the tunnel, glowing so bright that Edelgard's vision washed out in white. She braced herself, knife at her arm, ready to call on her twice-cursed Crest, when the power fell apart in sluggish pink threads. 

"Ow!" Hilda muttered a curse under her breath. "Okay, no big gestures in the weird tunnel. Got it."

Edelgard paused, considering whether or not to speak again. She didn't want to reveal her identity, but clearly— _somehow_ —Hilda Valentine Goneril also had magic, and she hadn't known that until this very moment. "I'd appreciate you not trying to kill me when we're both stuck."

"Edelgard?" Hilda's shock translated through the shadows with ease. "Wait, seriously? You're the one scurrying around under here and terrifying the masses? I didn't see that coming."

"I'm not terrifying anyone," Edelgard murmured. "No one else was supposed to know these tunnels existed."

"Hate to burst your bubble, Hresvelg, but half the school causes some kind of trouble down here. Solstices. Full moons. You know, when the stars are aligned and everyone's panicking over finals."

She blinked. If other people had been experimenting with the crystals here, using them for such purpose, it would explain their staggered decline. "Can we discuss this outside? I am...not fond of the dark."

Hilda was quiet for a minute, then the scrape of hands on earth returned. "Yeah, I think I can wriggle backwards out of here. Follow the leader."

They emerged at the drain-off pipe, covered in dirt, but Hilda looked a bit worse for wear. Her clothes were more suited for a quick session at the gym than underground adventuring, with a few scrapes and bruises to show for it.

"It really is you." Hilda smiled. "Which is wild. You're Miss Rationality in all our classes."

"Magic is perfectly rational," Edelgard retorted. "The social structures around it are another story."

Her first instinct was to demand secrecy, but Hilda had already played her hand. They were both guilty, and thus had no reason to expose one another.

Hilda tilted her head. "Want to share what you were very rationally doing down there? Your jacket's covered in weird red dust, and I see that knife."

"It doesn't matter." Edelgard closed the knife in question, tucking it away. "I need to get back to my dorm."

"It _does_ matter, because there's some real bizarre shit going on here, and from my investigation, you're right in the middle of it." Hilda straightened up, exaggerating the difference in height between them; it was greater than Edelgard would have liked. "So spill. Hubert's not here to hex me."

Damn it, she knew about Hubert too? This was swiftly falling out of control. "Whatever you're trying to find out, I'm not involved. This is personal, Hilda. I'm not trying to conquer the school."

"Yet," Hilda countered, tone teasing despite the sharp look in her eyes. "I've seen you and Rhea going at it. Not much for the president, huh?"

Well, that was another matter entirely. "I'm trying to keep someone safe and healthy, Hilda. That's all. Someone I really care about."

That earned a curious hum. "All right. Give me the name and I'll let you go."

"It's none of your business," Edelgard growled.

Hilda crossed her arms, shoulders straining against her shirt. "My brother almost got eaten alive his senior year here by _something_. Claude's keeping tabs on disappearing students. You're running around doing weird crystal nonsense behind everyone's backs. I'm making it my business."

"Fine." Edelgard's eyes narrowed. "But if you can't be of any help, you have to leave. Immediately."

Surprisingly, Hilda agreed without another word of protest, and Edelgard considered she might have gotten the lesser end of the bargain. She weaved her way back to the dorms, then knocked gently on the door of the room she shared with Lysithea.

"You don't have to knock," a breathy, amused voice carried from the other side. "It's not like I'm naked."

Edelgard blushed, wishing very much that Hilda hadn't been in earshot of that, but the taller girl's grin was unmistakable. "I have company."

Lysithea let out a startled sound as Edelgard opened the door, brusquely shepherding Hilda inside. Books and tablets were everywhere, countless notes surrounding Lysithea's bed like a twisting halo. She was under the blankets with two screens propped on her lap, one displaying a lost text on blood sorcery, the other focused on chemistry homework.

"Holy..." Hilda stopped in the middle of the room, eyes wide. "Okay. You know, this doesn't convince me that the two of you aren't trying to drag the school into the abyss."

"What is she doing here?" Lysithea asked, eyes wide. "Edelgard, no one can—"

"She knows," Edelgard interrupted gently. "We met each other in the tunnels."

"Wow. I thought you two were dating because of the cute shared haircolor thing, but this is something else." Hilda leaned over to see Lysithea's tablets. "400 level chem _and_ Macuil's Theorem? Your head must be about to explode."

Lysithea turned off both screens with a tap of her fingers. "What would you know about it?"

The question earned a laugh. "Babe, I come from three generations of Goneril alchemists. I'm pretty sure my twice-removed grandfather was hanging out with Macuil."

"Oh." Lysithea blinked, her face a touch pink. "No offense, but you just got a lot more interesting."

"None taken. I try not to advertise the prodigy thing, because it makes folks think I can brew a Philosopher's Stone or some shit." Hilda's lips pursed. "Okay, I did turn water to wine once, but that's not actually super hard."

Edelgard had to quietly agree: Hilda was suddenly the most interesting one in the room. "Have you ever tried to alter a Crest?"

Hilda coughed, looking surprised. "Uh, no. I like mine right where it is, thank you."

"That's because yours isn't killing you," Lysithea countered, voice soft.

All the humor drained out of Hilda's face as she looked between the two of them. "Oh, I got it. Explains the knife Edelgard was carrying around."

"Yes," Edelgard said. "We've been trying to find a cure, a fix. Anything to stop the magic from eating away at us, but some crucial element is missing."

"Yeah, I mean, blood alone is never going to cut it." Hilda shrugged, as if it was the most obvious thing in the world. "You're trying to fight fire with fire. Or well, body with body. Maybe a little mind with mind."

Lysithea sat up in bed, the most energetic that Edelgard had seen her in days. "You're talking about alchemical primes."

"Duh. You're never going to overwhelm an imbalance with another imbalance." Hilda smiled. "But I'd be happy to be the soul in this situation. A little sulfur, get your fire going?"

Edelgard felt her face heat up, and was even more flustered to see Lysithea in much the same state. Hilda, on the other hand, was overjoyed.

"Oh you two are _adorable_." A smirk rose to her lips. "Yeah, I'm in. I help you, and make sure you're not summoning big dark monsters out from under the school's foundation. Sound good?"

After several internal attempts to summon an argument, Edelgard gave up. It had been a long night. "Sounds great."

—


End file.
